Monday, March 31, 2008

"The Bible speaks for itself at the Creation Museum.We’ve just paved the way to a greater understanding of the tenets of creation and redemption. Our exhibit halls are gilded with truth our gardens teem with the visible signs of life. We invite you to visit the Creation Museum. Your life may change forever."

"The Creation Museum is a 60,000 square foot museum in the United States designed to promote young Earth creationsim. The museum presents an account of the origins of the universe, life, mankind, and man's early history according to a literal reading of the book of Genesis. Its exhibits reject evolution and assert that the earth and all of its life forms were created in 6 days just 6000 years ago and that man and dinosaurs once coexisted. These views disagree with well in excess of 99% of the scientists in relevant fields. Also, the museum exhibits are at odds with the vast majority of scientists who accept that the Earth is approximately 4.5 billion years old, and that the dinosaurs became extinct 65.5 million years before human beings arose.The museum has generated criticism by the scientific community, several groups of educators, Christian groups opposed to young Earth creationism, and in the general press.

The museum, which is said to have cost $27 million, is privately-funded through donations and opened its doors to the public on May 28, 2007. Based on projections, the museum anticipated 250,000 paying visitors in its first year of operation.Total attendance at the museum surpassed 100,000 visitors on July 21, 2007 and 200,000 visitors on September 20, 2007. Visitor attendance also exceeded first year expectations only 5 months and 5 days after opening, with a total of 250,000 visitors on November 2, 2007."

This is a video about the evolution of a complex eye structure. It explains how a group of light-sensitive cells could be favored in primitive animals and, over time, develop into the complex eye we now possess (though it pales in comparison to many other critters like raptors). Given millions of years, I think it's pretty feasible.

Monday, March 24, 2008

"The magic of the microscope is not that it makes little creatures larger, but that it makes a large one smaller. We are too big for our world. The microscope takes us down from our proud and lonely immensity and makes us, for a time, fellow citizens with the great majority of living things. It lets us share with them the strange and beautiful world where a meter amounts to a mile and yesterday was years ago."-From the book “Mites of Moths and Butterflies”

This is an animal I wouldn’t want to meet if I were tiny. Though they are small — a fully-grown adult has a shell just 2 centimeters (three quarters of an inch) across — they can see off a lizard that intrudes on their plant, and they can kill large centipedes, so they’d make mincemeat of little me.

All the same, I like them because they are unusual in two ways. First: their habitat. Most crabs live in the ocean or, if they’re really adventurous, in burrows they dig on a beach; a few live in (or near) streams and lakes. But M. depressus has evolved to exploit the bromeliad pools, and as far as anyone knows, they do so exclusively.

And here’s the other oddity: in this species, mothers look after their young.

Crabs aren’t famous for paying attention to their offspring. In most species, the female carries her eggs until they are ready to hatch, then releases the larvae into the ocean, where they fend for themselves. The numbers can be enormous — female blue crabs (Callinectes sapidus), for instance, can release two million larvae in one go. (After fertilizing all those eggs, the male needs 15 days to replenish his sperm supplies, poor fellow.)

M. depressus is different. The female lavishes attention on her young. She chooses her plant carefully — she prefers plants with larger volumes of water — and then prepares the pool that will be the nursery. She fishes out any dead leaves that may have fallen in, and drops them onto the ground. (If a sneaky experimenter puts leaves back in, she’ll remove them.) And she drops empty snail shells into the water, often after capturing and feasting on the owners.

These behaviors have two effects. Removing the leaves increases the amount of oxygen in the water; crab larvae need high levels of oxygen in order to breathe. The added snail shells increase the levels of calcium, a mineral without which baby crabs can’t make shells of their own. Unimproved pools can’t sustain baby crabs.

And the hard work doesn’t stop there. For several weeks, the mother feeds her young — perhaps as many as 90 of them (which sounds a lot — but is a lot less than two million) — on cockroaches and millipedes that she catches. And she protects them from being eaten by predators, especially hungry damselfly larvae.

Damselfly larvae generally live in streams, ponds, and lakes; but some have evolved to inhabit bromeliad pools. Among them: Diceratobasis macrogaster. Given a chance, one of these larvae will eat as many as five baby crabs a day. The mother crab does not give them that chance; but an orphaned brood will perish quickly.

Even more unusual, the young crabs don’t disperse immediately, but remain with mom; sometimes you’ll find a couple of generations living together. This is probably because small crabs are more vulnerable to attack as they search for plants of their own, and so it makes sense to grow up before leaving. But whatever the reason, living in family groups is the first evolutionary step towards complicated social arrangements, such as those common among termites and the ants, bees and wasps, but rare for other insects or crustaceans. Perhaps one day, if the evolutionary pressures are right, crabs might join the list of highly social creatures.

Saturday, March 22, 2008

The mantis shrimp (which oddly is neither a mantis nor a shrimp, but a crustacean that resembles both) has arguably the most complicated visual system of any animal on Earth. Its compound eyes sit on independently moving stalks and can see colors ranging from ultra-violet to infra-red. Each eye is divided into three regions for tracking motion, forms, depth, and color. All of this, it is theorized, is done without the aid of its tiny brain. (It’s also got claws that can smash through glass, but that we’ll save for another article). Now add to this an entirely new kind of vision previously unknown: the mantis shrimp can see circular polarized light.

We humans can see the effects of linear polarized light when we put on polarized sunglasses and go out on a boat. Linear polarization is observed when transparent materials reflect light, so on a sunny day, the ocean’s surface will look glassy to us. Put on polarized sunglasses and the glare is eliminated. Circular polarization is a bit more complicated. It has to do with out-of-phase stereo imaging, which can best be explained by the effect you get when you put on 3-D glasses and watch a movie in 3-D. That’s circular polarization.

Why the mantis shrimp has the ability to, in effect, put on 3-D glasses is still a mystery. But Professor Justin Marshall (the researcher who discovered it), from the Queensland Brain Institute, surmises it has something to do with sex. Only the males are able to see this way, so his theory is it is some as of yet unknown communication for mating. "[We] humans only have three color channels," he said. "These little guys have 12, and can see both linear and circular polarized light—it is remarkable."

Wednesday, March 12, 2008

Sunflower sea stars are large predators of the sea floor, reaching arm spans of up to three feet. They are surprisingly fast, voracious hunters for clams, urchins, snails, abalone, sea cucumbers, and other sea stars. Adult sunflower sea stars can move at the astonishing speed of one meter per minute using 15,000 tube feet which line the undersides of their bodies.

The following video uses time-lapse photography to capture this beautiful animal in hot pursuit of lunch. Sea stars have two stomachs - one is used for digestion, and the other stomach can be extended outward to engulf and digest prey. The latter is highly specialized, and uses digestive enzymes to liquefy its prey before complete digestion. After protruding from the mouth, the stomach can be stretched so thin that it can fit into the thin opening of a mussel or clam shell! Once the stomach has entered the shell, the digestive enzymes liquefy the prey within its own shell. The liquids are fully digested when the stomach retracts back into the body of the sea star.

Wednesday, March 5, 2008

In Kingdom Animalia, penises are for more than just sperm delivery. If females mate with a number of males, each subsequent suitor will sire a larger proportion of her children if his sperm are the ones that do the trick. A male who can stimulate his mate to take up more of his sperm, or who can somehow get rid of the sperm of his rivals, will spread more of his genes than less artful fellows. Thus, the first consequence of female promiscuity is that males are under greater pressure to outdo one another in all aspects of love. For this task, the penis is an important tool.

Bushbabies and many other primates have monstrous penises – many of them look like medieval torture instruments. They have spikes and knobs and bristles and are often twisted into weird and sinister shapes. By comparison, the human penis is dull, notable only for its girth.

Among primates as among insects, it is a rule of thumb that in species where females consort with one male at a time, penises are small and uninteresting. Take the gorilla – a huge guy with a little teeny weenie. A male gorilla can weigh 210kg (460lbs), but his penis is a measly 5cm (2in) long and entirely devoid of knobs and spikes. The Argentine lake duck puts him to shame. The duck is small, but his penis, which rivals that of the ostrich, is 20cm (8in) long – and it has spines. But then a male gorilla generally presides over a small group and does not often have to worry about other fellows’ sperm.

Damselflies, on the other hand, have evolved some of the fanciest penises around. A typical damselfly penis has a balloon – an inflatable bulb – and two horns at the tip, plus long bristles down the sides. In the black-winged damselfly, Calopteryx maculate, the male uses this device to scour sperm from inside a female before depositing his own. But in the related Calopteryx haemorrhoidalis asturica, he uses his penis as an instrument of persuasion: by stimulating her in the proper manner, he can induce her to eject sperm from previous lovers.

Meanwhile, the moth Olceclostera seraphica has genitals that resemble a musical instrument: the male rubs one part of his privates against another, producing vibrations with which to thrill his mate.

In contrast, among termites the female typically mates with only one male – and male termites have plain, unadorned genitalia that do not differ much from one species to the next.

Bar the doors and break out the chastity belts, boys, because girls of most species sleep around, and it's for their own good, if not yours.

For generations, biologists had assumed females to be naturally chaste, while males were renowned for their promiscuity. Even Charles Darwin, who invented the idea of sexual selection, didn't dare challenge the Victorian morals of his day. Man evolved from ape, fine. But an immodest and lustful Mother Nature? Heaven forbid!

Now, hundreds of studies and a spate of books are challenging that conventional wisdom. Females of many species, it turns out, have evolved strategies for passing on their genes that involve copulating with multiple males -- and recognition of that fact is literally changing our view of the birds and the bees.

"Natural selection, it seems, often smiles on strumpets," says evolutionary biologist Olivia Judson, author of "Dr. Tatiana's Sex Advice to All Creation," the most recent and entertaining book exploring the variety of female harlotry.

"As a rule, loose females have more and healthier children."

To be sure, biologists are examining these questions in the dispassionate light of scientific inquiry. In describing their theories, they prefer the more neutral term "polyandry," meaning many males, instead of "promiscuity." And they caution laypeople not to look to nature's own apparent infidelities for any justification of their own behavior.

The misbegotten idea that males evolved to make love and females to demur gained scientific currency in the late 1940s in fruit fly experiments by Angus Bateman, a British scientist who reached his erroneous conclusions in part because his experiments lasted only three or four days.

Had he run his experiments longer, he might have discovered that male black- bellied fruit flies secrete an anti-aphrodisiac in their semen that's relatively short lived. As soon as it runs out, females become interested in copulating again.

On the surface, the conventional view made sense. Sperm seemed to come cheap to males, while eggs were expensive to females, which have to invest the time to raise offspring. Scientists could not fathom any possible benefit of multiple partners of females, and they could come up with plenty of potential costs, such as sexually transmitted diseases.

BIRDS DO IT

Then came DNA paternity testing. In one species after another, it turned out that biologists were as cuckolded as the males they had been observing. The first and most extensive examples of polyandry were found among avian species, which was quite a shock to scientists because birds had appeared to be paragons of traditional family values.

"The way the male and female rush back and forth to their demanding brood of chicks seems like nature's model of good parenting," says Marlene Zuk, biology professor at UC Riverside and author of "Sexual Selections: What We Can and Can't Learn About Sex From Animals."

"Now, we find that they're actually in the same situation as millions of modern-day husbands and wives, eyeing a child warily and making uneasy jokes about the milkman," she says.

DNA testing in chicks of seemingly monogamous females showed a wide range of extra mates. In one study, for example, as much as 90 percent of the offspring of the brilliantly colored Australian fairy wren were from mates other than the presumed father.

Biologists have struggled to come up with broad theories for why females benefit from playing the field, but so far the reasons seem to vary widely according to species. A lot of complex theory boils down to this: A gal's got to do what's necessary to ensure the survival of her genes.

In some cases, females may get more help around the home. Among bronze- winged jacana, for example, harems of up to four males do all the child care, enabling a female to have four times as many broods. Male greater rheas, flightless South American birds that resemble ostriches, receive eggs from several females, incubate them and rear all the chicks, while females go off to mate and lay other clutches.

In other cases, females swap sex for food -- the more sex, the more food and the healthier their offspring.

Among green-veined white butterflies, for example, a virgin male ejaculates a sperm packet roughly 15 percent of his weight that also contains nutritious substances. Females that have sex with several virgins lay more and bigger eggs than those that do it with only one or with males that have lost their virginity and consequently make sperm packets only half the size of their virgin glory.

SURVIVAL OF THE LOOSEST

In other cases, promiscuity is simply a matter of survival. Male chimpanzees, for example, have been known to kill infants not their own. Frequent sex with several males -- in one 15-minute period, a female was observed having sex with eight males -- can heroically confuse paternity and act as insurance against harm to her offspring.

But while females are busy ensuring their genetic survival by sleeping around, males have not been idle. After all, female promiscuity puts the genes of males at risk. It's no good being Don Juan, seducing all the females in sight, if none of them uses your sperm, Judson says. So males have developed counterstrategies to ensure their genetic survival.

"This is perhaps the most significant discovery of the past two decades, that male and female attributes coevolve," writes Tim Birkhead, professor of behavioral ecology at the University of Sheffield in Britain and author of "Promiscuity: An Evolutionary History of Sperm Competition."

Monday, March 3, 2008

I'm a European praying mantis, and I've noticed I enjoy sex more if I bite my lovers' heads off first. It's because when I decapitate them they go into the most thrilling spasms. Somehow they seem less inhibited, more urgent - it's fabulous. Do you find this too?

I Like 'Em Headless in Lisbon

Males of your species are boring lovers. Beheading them works wonders: whereas a headless chicken rushes wildly about, a headless mantis thrashes in a sexual frenzy. Why can't he be that way when he's whole? Well, it's hard to have wild sex if you're trying to keep your head.

A male praying mantis is in danger during his approach and his departure, but while he's actually on your back-the position in which intact males have sex- you cannot attack him. However, you do not need him intact to have sex with him. If you rip his head off on the approach, his body will go into spasms that allow his genitalia to connect with yours. Unsurprisingly, though, he does not want to have his head removed. Put yourself in his place - you'd be trembling to the tips of your antennae.

Saturday, March 1, 2008

Eusocial animals are an anomaly within Kindgom Animalia because an individual will put its energy towards helping another reproduce instead of placing that energy towards the perpetuation of its own genes. Within a colony of naked mole-rats, only one female will mate with her few chosen consorts, and the young from previous litters maintain and defend the colony and assist in rearing newborns. They essentially sacrifice their own opportunities to survive and reproduce for the good of other colony members.

The naked mole-rats are the only known mammal to display this odd behavior. We see eusocial systems in Class Insecta, Order Hymenoptera: bees, wasps, and ants. Why be eusocial? The reason is that by helping the queen reproduce offspring, it may contribute more to future generations of the species than actually reproducing themselves.

Naked mole-rats’ native range is in Kenya, Ethiopia and Somalia. They are exclusively fossorial, or underground, rodents that eat primarily the succulent tubers that are formed by many of the plant species that grow in arid areas. They obtain all the water they need through their food- they do not drink! When a group of mole-rats finds a large tuber, which may be more than a foot in diameter, they generally bore through it, eating mainly the interior flesh while leaving the thin epidermis intact. This behavior may allow the plant to remain healthy for some time- even to continue growing- thereby providing a long-term food resource for the colony.

(They also regularly practice coprophagy, the reingestion of feces, which allows them to maximize their uptake of nutrients from their food.)

"When the rains come, the eusocial mole rats cooperate and teams of animals dig like the fury," said Dr. Paul W. Sherman, a behavioral ecologist and Cornell professor of neurobiology and behavior. "Together, they are more likely than a solitary mole rat to find a bonanza of tubers to sustain the colony until the next rain. Alone, individuals would starve in that environment. And with a 'super mom' to produce more helpers, individuals willingly give up personal reproduction for indirect reproduction through relatives."

This video feature this odd rodent: hairless, with sensory hairs on their nose and tail (which allows them to move deliberately backwards and forwards) . Their large incisor teeth sit outside their lips so they can gnaw comfortably through the toughest tuber. They are adorable. Enjoy!

About Me

"We need another and a wiser and perhaps a more mystical concept of animals. Remote from universal nature, and living by complicated artifice, man in civilization surveys the creature through the glass of his knowledge and sees thereby a feather magnified and the whole image in distortion. We patronize them for their incompleteness, for their tragic fate of having taken form so far below ourselves. And therein we err, and greatly err. For the animal shall not be measured by man. In a world older and more complete than ours, they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life, fellow prisoners of the splendor and travail of the earth."
--Henry Beston, 1928